A highly atom-economical enantioselective organocatalyzed Rauhut-Currier and [3+2] annulation sequence has been established by using a flow system. Suitable flow conditions were explored through reaction screening of multiple parameters using machine learning. Eventually, functionalized chiral spirooxindole analogues were obtained in high yield with good ee as a single diastereomer within one minute.
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http://dx.doi.org/10.1039/c9cc08526b | DOI Listing |
Molecules
January 2025
Department of Pharmacy, Jilin Medical University, Jilin 132013, China.
An efficient stereoselective synthesis of 10-hydroxy-10-(1-indol-3-yl)-9-(10)-phenanthrene derivatives was realized through an organocatalyzed Friedel-Crafts reaction of phenanthrenequinones and indoles using a (,)-dimethylaminocyclohexyl-squaramide as the catalyst. Under the optimized conditions, the desired chiral products were obtained in good yields (73-90%) with moderate to high ee values (up to 97% ee). Two pairs of synthesized enantiomers were subjected to evaluation of their antiproliferative activities on four types of human cancer cell lines and one human umbilical vein endothelial cell line using the CCK-8 assay.
View Article and Find Full Text PDFBeilstein J Org Chem
December 2024
Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá (IRYCIS), 28805 Madrid, Spain.
Asymmetric cycloaddition is a straightforward strategy which enables the synthesis of structurally distinct cyclic derivatives which are difficult to access by other methodologies, using an efficient and atom-economical path from simple precursors. In recent years several asymmetric catalytic cyclization strategies have been accomplished for the construction of -heterocycles using various catalytic systems such as chiral metal catalysts, chiral Lewis acids or chiral organocatalysts. This review presents an overview of the recent advances in enantioselective cyclization reactions of 1-azadienes catalyzed by non-covalent organocatalysts.
View Article and Find Full Text PDFOrg Lett
December 2024
Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences & Research Unit of Peptide Science, Chinese Academy of Medical Sciences, 2019RU066, Lanzhou University, Lanzhou 730000, China.
To advance more efficient dearomatization approaches, we present herein an organocatalyzed asymmetric double dearomatization reaction of tricyclic phenols and alkoxybenzenes by leveraging a novel steric hindrance-regulated dearomatization strategy for nonfunctionalized phenols. This protocol allows the efficient synthesis of structurally complex polycyclic diketones with four tertiary carbon centers under mild conditions while also showcasing the potential of multiple dearomatizations for building intricate molecular frameworks from simple starting materials.
View Article and Find Full Text PDFSci Adv
November 2024
Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China.
Despite the considerable potential applications for helically chiral molecules across various sectors, their catalytic asymmetric synthesis remains nascent and has seen very limited advancement compared to that of central and axial chiral compounds, primarily owing to the scarcity of available starting materials and the immense challenges associated with achieving stereochemical control. Herein, we report an innovative approach to the facile synthesis and catalytic kinetic resolution of uniquely structured and stereochemically complex helical polycyclic phenols by using a steric hindrance-regulated enantioselective dearomative amination reaction. The distinguished aspects of this method include the exceptional stability of the dearomatized products and impressive versatility of the recovered substrates in the construction of enantioenriched helical frameworks.
View Article and Find Full Text PDFMolecules
October 2024
School of Chemistry and Chemical Engineering, Beijing Institute of Technology, No. 5 Zhongguancun South Street, Beijing 100081, China.
An organocatalytic enantioselective [3+2] cycloaddition reaction involving 2-arylidene-1,3-indandiones and -2,2-difluoroethylbenzothiophenone imines was developed. This approach efficiently afforded dispiro[benzothiophenone-indandione-pyrrolidine]s, featuring three stereocenters, in 84-98% yields with 3-93% ee and 9:1->20:1 dr. Notably, the method maintained its yield and enantioselectivity integrity even in a gram-scale amplification experiment.
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